Sidewalk



(No Model.)

o. QGILMAN.

SIDE'WALK. No, 340,569. Patented APL 27, 1886.

N, FETTS. PMo-Ufhgnphef. Washingian. D. C.

UNITED STATES PATENT OEEICE.`

CHARLES CARROLL GILMAN, OF ELDORA, IOVA.

SIDEWALK.

SPECIFICATION forming part of Letters Patent No. 340,569, dated April 27, 1886.

Application filed October 15, 1585. Serial. No. 179.917. (No model.)

T0 @ZZ whom it nuty concern/ Be it known that I, CHARLEs CARROLL GILMAN, a citizen of the United States, and a resident of Eldora, Hardin county, Iowa, have invented a new and useful Improvement in Sidewalks, of which the following is a specitlcation.

The object of my invention is to construct a cheap and durable sidewalk having an indestructible and water-p roof foundation which cannot be washed away by the action of water; and to this end my invention consists in using as a foundation for a surface layer of asphalt mastic or cement, blocks or slabs of terra-cotta lumber or porous terra-cotta satu` rated or impregnated with asphaltum.

The accompanying drawing represents a crosssection of a sidewalk constructed in accordance with my invention.

rllhe foundation of my sidewalk consists of blocks, A A, of terra-cotta lumber or porous terracotta, preferably three inches in thickness, about twelve inches wide, and from sixteen to thirty inches long. Said blocks are saturated or impregnated with asphaltum. In order to thoroughly impregnate the slabs of said material with the asphaltum, I place the former in a closed tube, vessel, or receiver, from which I exhaust the air, and then admit thereto the hot melted asphaltum, the same being forced by the atmospheric pressure into the pores or cells (exhausted of air) of the terra-cotta lumber, the latter beingheated to about the same or greater' temperature as the said asphaltum, to avoid chilling the latter.

The method j ust described is similar to the well-known process employed in impregnating wood with creosote, and since no claim is laid to said method, a fuller description thereof is not essential to an understanding of this invention.

The saturated terracotta lumber, after it has cooled and the asphaltum hardened or become solid, is in fact a new material, which is much stronger and of greater weight than the unimpregnated material, is absolutely impervious to moisture, cannot decay, and is practically indestructible.

The said slabs or blocks, treated as described, are arranged in two layers, so as to break joints with each other in both directions. The lower blocks, A', rest preferably 011 a foundation of sand or gravel, B. These two layers of indestructible and water-proof material make a solid foundation for the surface covering. The upper blocks, A, are covered with a layer of asphalt mastic, C, con1- posed of asphalt, gravehand pounded limestone. This mastic is rolled over the same to a thickness of from one to two inches, varying according to circumstances.

I do not wish to limit myself to a formation consisting of two layers of blocks, as one layer of thicker blocks may be used, or the blocks may be formed so as to have a bearing on each other; butthe construction illustrated is much to be preferred. Neither do I desire to limit myself to a wearing-surface of asphalt mastic, for a layer-of cement may be used in lieu thereof. It is evident, also, that my invention is applicable to street-pavements as well as to sidewalks; but inthe construction of pavements a strongerfoundation and a thicker layer of asphalt mastic is used.

I am aware that ordinary building-bricks have been immersed in a liquid solution of alum, borax, copperas, axnl'water, and after drying boiled in a mixture of lcaoutchouc and coaltar, and that it has been proposed to use such bricks as the surface layerof a pavement or sidewalk. I am also aware that it has been proposed to lay a surface layer of terra-cotta blocks upon a foundation of bricks, and also that it is not new to cure a brick by immerA sion in a mixture of coal-tar, bitumen, pinegum, and alum; and these several things I do notclaim.

I am aware that a-roller-skating surface has been formed by laying 011 a foundation of ordinary brick a composition of asphalt, bitumen, and resinous oil; but this I. do not claim, as it is entirely different froln my invention.

Having thus described my invention, what I claim, and desire to secure by Letters Patent, 1s-

1. A sidewalk or pavement consisting of a surface layer of asphalt mastic or its equivalent and a foundation composed of slabs or blocks of terracotta lumber saturated or iml break joints with each other in both direcpregnated with asphaltum, substantially as detions, substantially as described. 1o scribed. In testimony whereof I have signed my name 2. A sidewalk or pavement consisting of a in the presence of two witnesses. 5 surface layer of asphalt mastic or its equiva- CHARLES CARROLL GILMAN.

lent and a foundation composed of two layers Witnesses: of blocks of terra-cotta lumber saturated or SAML. G. SLOAN,

impregnated with asphaltum and arranged to H. H. GALUsHA. 

